There is a requirement to be able to screen cargo items for the presence of illicit materials and devices for the protection of the public.
Currently, such inspection may be undertaken using X-ray based screening apparatus. In these systems, an X-ray image of the object under inspection is taken and an operator reviews this image to resolve, in their experience, whether the cargo is clear for onwards travel or whether the cargo requires a further level of inspection. However greater volumes of cargo traffic and greater desire and need for security scanning have lead to an increasing need to increase the throughput of scanning systems.